In the group the reactivity of metals increases? give example

As sodium and potassium both are alkali metals that belong to Group IA of the periodic table. They have one valence electron in their valence shell. As we move from top to bottom, the reactivity of metallic elements of Group IA increases.

water is used to store them because it would keep the radiation from getting out in the open and causing harm to the workers

sry but any answer choices